Fabrication of sub-100 nm GaAs columns by reactive ion etching using Au islands as etching mask

Abstract

A new method for fabrication of reactive ion etching masks for nanoscale GaAs columns is proposed. The mask consists of sub-100 nm Au islands formed by in situ heating a thin gold film on the substrate surface. The resulting areal density of the Au islands can exceed 1010 cm−2. The islands show good resistance against etching, making the method suitable for fabrication of nanoscale structures with very high aspect ratios. This is demonstrated by etching over 1 μm high GaAs and AlGaAs/GaAs columns with widths below 100 nm.